This kind of pigments are abnormal substances that can not be metabolized or removed . Can be exogenous or endogenous , and its accumulation is not exclusively pathogenic.
 

As an example of exogenous pigments have coal and tattoo. Pigments such as melanin, lipofuscin and hemoglobin derivatives are endogenous .
 

The main pigments are derivatives of hemoglobin, i.e., hemosiderin and bilirubin . Let's put this topic in these two pigments .

Hemosiderin , then, is a storage form of iron . Thus , this pigment is present in places with too much iron . This derivative of hemoglobin can accumulate due to excessive destruction of red blood cells and the excessive absorption of iron from the gut .

Bilirubin also derives from the heme fraction of hemoglobin and undergoes a process of conjugation in the liver that is essential for the formation of bile acids . When the concentration of bilirubin in the blood is higher than 3 mg / dL , there is a diagnosis of jaundice.
 

Jaundice can be divided into three types : pre -hepatic , hepatic and post- Hepatocytic . Taking into consideration the employees suffixes, we can already see the difference between the classes of jaundice .
 

The prehepatic occurs when there is an intensive hemolysis , so that the amount of released exceeds the capacity of bilirubin conjugation and elimination by the liver. Therefore, there is a predominance of unconjugated bilirubin .
 

The hepatocytic occurs when there is a direct injury to hepatocytes , thus preventing the metabolism of bilirubin. There is an accumulation of conjugated bilirubin and unconjugated .
 

Meanwhile, when there is obstruction in the normal flow of bile , the bilirubin does not reach the intestine and thus accumulates causing post -hepatic jaundice.

 

 

 

 

Bibliography:

 

KUMAR V, ABBAS AK, FAUSTO N. Robbins & Cotran: Bases Patológicas das Doenças. 8ª edição. Rio de Janeiro: Elsevier, 2008.

BRASILEIRO FILHO, G. Bogliolo: Patologia. 7ª edição. Rio de Janeiro: Guanabara Koogan, 2006.
RUBIN E, GORSTEIN F, RUBIN R, SCHWARTING R, STRAYER D. Rubin: Bases Clínico-Patológicas da Medicina. 4ª edição. Rio de Janeiro: Guanabara Koogan, 2006.
BRASILEIRO FILHO, G. Bogliolo: Patologia Geral. 4ª edição. Rio de Janeiro: Guanabara Koogan, 2009.
MONTENEGRO MR, FRANCO M. Patologia: Processos Gerais. 4ª edição. São Paulo: Atheneu, 1999.